Characterization of cross-section correction to charge exchange recombination spectroscopy rotation measurements using co- and counter-neutral-beam views
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)
Measurements of rotation using charge exchange recombination spectroscopy can be affected by the energy dependence of the charge exchange cross section. On DIII-D, the associated correction to the rotation can exceed 100 km/s at high temperatures. In reactor-relevant low rotation conditions, the correction can be several times larger than the actual plasma rotation and therefore must be carefully validated. New chords have been added to the DIII-D CER diagnostic to view the counter-neutral-beam line. The addition of these views allows determination of the toroidal rotation without depending on detailed atomic physics calculations, while also allowing experimental characterization of the atomic physics. A database of rotation comparisons from the two views shows that the calculated cross-section correction can adequately describe the measurements, although there is a tendency for 'overcorrection'. In cases where accuracy better than about 15% is desired, relying on calculation of the cross-section correction may be insufficient.
- OSTI ID:
- 21266685
- Journal Information:
- Review of Scientific Instruments, Vol. 79, Issue 10; Conference: HTPD08: 17. topical conference on high-temperature plasma diagnostics, Albuquerque, NM (United States), 11-15 May 2008; Other Information: DOI: 10.1063/1.2957841; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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